Severe Fetal Symptomatic Infection from Human Cytomegalovirus following Nonprimary Maternal Infection: Report of Two Cases.

INTRODUCTION: Human cytomegalovirus (HCMV) is the most common congenital infection, especially severe after a maternal primary infection; sequelae in neonates born to mothers experiencing a nonprimary infection have been already reported. Hereby, two cases of severe fetal HCMV disease in seroimmune gravidas referred to our Unit are described. CASES PRESENTATION: Case 1: A fetus at 21 weeks' gestation with signs of anemia and brain abnormalities at ultrasound, described at magnetic resonance (MR) imaging as ependymal irregularity and bilateral asymmetric parenchymal thinning; amniotic fluid sample was positive for HCMV although the woman had a previous immunity; after termination of pregnancy, autopsy demonstrated a thicken layer of disorganized neurons on the right cortical plate, while on the left, there was a morphological pattern coherent with polymicrogyria. Case 2: A fetus at 20 weeks' gestation with anemia, moderate atrioventricular insufficiency, hepatosplenomegaly but no major cerebral lesions. Fetal blood was positive for HCMV, although unexpected for prepregnancy maternal immunity, and intrauterine transfusion was needed. A cesarean section at 34 weeks' gestation was performed due to worsening condition of the fetus, who had a birthweight of 2,210 g and needed platelet transfusions, but MR examination and clinical evaluation were normal. CONCLUSION: The impact of nonprimary maternal infection on pregnancy outcome is unknown and fetal brain damage in HCMV seroimmune transmitter-mothers can occur as a consequence of maternal reinfection or reactivation for a hypotetic different role of HCMV-primed CD4+ or CD8+ T-cells in fetal brain, with progressive brain lesions coexistent in the first case and with severe unexpected anemia in the second case. A previous maternal HCMV immunity should not exempt to test anemic fetuses for such infection, nor to consider a potential transplacental transmission.

Cerebellar dysplasia related to PIK3CA mutation: a three-case series.

The term PROS (PIK3CA-Related Overgrowth Spectrum) indicates a wide spectrum of overgrowth disorders related to somatic mutations in PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha) pathway. We present three cases with PIK3CA mutation and clinical characteristics encompassing MCAP (megalencephaly-capillary malformation) condition but lacking all criteria to a certain diagnosis, most of all showing prevalent and peculiar involvement of cerebellar structures at MRI (magnetic resonance imaging) mainly consisting in cortical rim thickening and abnormal orientation of folia axis. These cases expand the spectrum of intracranial MRI features in PIK3CA disorders.

Fetal thick corpus callosum: new insights from neuroimaging and neuropathology in two cases and literature review.

PURPOSE: To describe the correlation between fetal imaging (in vivo and ex vivo) and neuropathology in two fetuses at early gestational age (GA) with isolated thick corpus callosum (CC), a rare finding whose pathological significance and neuropathology data are scarce. METHODS: Two fetuses at 21-week GA underwent fetal MRI (fMRI) for suspected callosal anomalies at ultrasound (US). After fMRI results, termination of pregnancy (TOP) was carried out and post-mortem MRI (pmMRI) was performed. Neuropathology correlation consisted in macro and microscopic evaluation with sections prepared for hematoxylin-eosin and immunohistochemistry staining. RESULTS: Fetal imaging confirmed in both cases the presence of a shorter and thicker CC with respect to the reference standard at the same GA, without a clear distinction between its different parts. Moreover, on pmMRI, an abnormal slightly T2-weighted hyperintense layer along the superior and inferior surface of CC was noted in both cases. At histopathology, these findings corresponded to an increased amount of white matter tracts but also to an abnormal representation of embryological structures that contribute to CC development, naming induseum griseum (IG) and the glioepithelial layer (GL) of the "callosal sling." After reviewing the literature data, we confirmed the recent embryological theory regarding the CC development and provide new insights into the pathophysiology of the abnormal cases. CONCLUSIONS: An abnormally thick CC at the early fetal period could be associated to an abnormal representation of the midline glia structures, so to result in potential disturbance of the axon guidance mechanism of callosal formation and eventually in CC dysgenesis.

Cobblestone-like brain malformation with a new bi-allelic ADGRG1 (GPR-56) mutation: Fetal imaging-pathology correlation.

BACKGROUND AND PURPOSE: Autosomal recessive cobblestone-like cortical malformation of the brain, with no eye or muscle involvement, has been reported in patients with biallelic mutations in ADGRG1 (formerly GPR56) and in other brain surface defects (eg, variants in COL3A1). We reported the intra-uterine brain MRI (iu-MRI), post-mortem MRI (pm-MRI), and neuropathology findings of a new ADGRG1 mutation in a fetus at early gestation. Imaging findings were compared with those of the sibling harboring the same mutation, to provide insights about the evolving morphology of such malformation. METHODS: A 21-week fetus underwent iu-MRI for a suspected cortical anomaly on ultrasound. After the MRI results, the termination of the pregnancy was carried out. A pm-MRI scan and autopsy were performed. A neuropathology-imaging correlation was achieved. The 5-year old sibling affected by developmental impairment also underwent a brain MRI. Both subjects underwent a genetic investigation. RESULTS: Two patterns of abnormality of the cerebral surface were identified on both fetal MRI: one at the vertex resembling a cobblestone-cortex due to neuronal overmigration into the subarchnoid space and the other in the occipital areas resembling polymicrogyria. These details closely matched the neuropathology findings. MRI findings of the sibling consisted of typical ADGRG1/GPR56-related brain findings showing a polymicrogyric-like cortex, also reported as bilateral frontal-parietal polymicrogyria. A flattened pons and small cerebellar vermis were present in both cases. Genetic testing demonstrated a novel homozygous variant c.1484T>C in the c gene in both cases. CONCLUSION: Our findings provide further evidence of the overlap of ADGRG1/GPR56-related brain dysgenesis with cobblestone-like cortical malformation of the brain.

A closer look at discordant placental echogenicity: two cases under the microscope.

Discordant placental echogenicity is observed in MC pregnancies complicated with twin anemia-polycythemia sequence, but could also belong to complicated singleton gestation.

L1CAM variants cause two distinct imaging phenotypes on fetal MRI.

Data on fetal MRI in L1 syndrome are scarce with relevant implications for parental counseling and surgical planning. We identified two fetal MR imaging patterns in 10 fetuses harboring L1CAM mutations: the first, observed in 9 fetuses was characterized by callosal anomalies, diencephalosynapsis, and a distinct brainstem malformation with diencephalic-mesencephalic junction dysplasia and brainstem kinking. Cerebellar vermis hypoplasia, aqueductal stenosis, obstructive hydrocephalus, and pontine hypoplasia were variably associated. The second pattern observed in one fetus was characterized by callosal dysgenesis, reduced white matter, and pontine hypoplasia. The identification of these features should alert clinicians to offer a prenatal L1CAM testing.

Hofbauer Cells and COVID-19 in Pregnancy.

CONTEXT.­: SARS-CoV-2 can undergo maternal-fetal transmission, heightening interest in the placental pathology findings from this infection. Transplacental SARS-CoV-2 transmission is typically accompanied by chronic histiocytic intervillositis together with necrosis and positivity of syncytiotrophoblast for SARS-CoV-2. Hofbauer cells are placental macrophages that have been involved in viral diseases, including HIV and Zika virus, but their involvement in SARS-CoV-2 is unknown. OBJECTIVE.­: To determine whether SARS-CoV-2 can extend beyond the syncytiotrophoblast to enter Hofbauer cells, endothelium, and other villous stromal cells in infected placentas of liveborn and stillborn infants. DESIGN.­: Case-based retrospective analysis by 29 perinatal and molecular pathology specialists of placental findings from a preselected cohort of 22 SARS-CoV-2-infected placentas delivered to pregnant women testing positive for SARS-CoV-2 from 7 countries. Molecular pathology methods were used to investigate viral involvement of Hofbauer cells, villous capillary endothelium, syncytiotrophoblast, and other fetal-derived cells. RESULTS.­: Chronic histiocytic intervillositis and trophoblast necrosis were present in all 22 placentas (100%). SARS-CoV-2 was identified in Hofbauer cells from 4 of 22 placentas (18.2%). Villous capillary endothelial staining was positive in 2 of 22 cases (9.1%), both of which also had viral positivity in Hofbauer cells. Syncytiotrophoblast staining occurred in 21 of 22 placentas (95.5%). Hofbauer cell hyperplasia was present in 3 of 22 placentas (13.6%). In the 7 cases having documented transplacental infection of the fetus, 2 (28.6%) occurred in placentas with Hofbauer cell staining positive for SARS-CoV-2. CONCLUSIONS.­: SARS-CoV-2 can extend beyond the trophoblast into the villous stroma, involving Hofbauer cells and capillary endothelial cells, in a small number of infected placentas. Most cases of SARS-CoV-2 transplacental fetal infection occur without Hofbauer cell involvement.

DNA vaccination against membrane-bound Kit ligand: a new approach to inhibiting tumour growth and angiogenesis.

A functional c-Kit/Kit ligand (KitL) signalling network is required for tumour angiogenesis and growth, and therefore the c-Kit/KitL system might well be a suitable target for the cancer immunotherapy approach. We herein describe a strategy that targets membrane-bound KitL (mbKitL) via DNA vaccination. The vaccination procedure generated antibodies which are able to detect mbKitL on human tumour endothelial cells (TECs) and on the breast cancer cell line: TSA. DNA vaccination, interferes with tumour vessel formation and transplanted tumour growth in vivo. Histological analysis demonstrates that, while tumour cell proliferation and vessel stabilisation are impaired, vessel permeability is increased in mice that produce mbKitL-targeting antibodies. We also demonstrate that vessel stabilisation and tumour growth require Akt activation in endothelial cells but not in pericytes. Moreover, we found that regulatory T cells (Treg) and tumour infiltrating inflammatory cells, involved in tumour growth and angiogenesis, were reduced in number in the tumour microenvironment of mice that generate anti-mbKitL antibodies. These data provide evidence that mbKitL targeted vaccination is an effective means of inhibiting tumour angiogenesis and growth.

rBet v 1 immunotherapy of sensitized mice with Streptococcus thermophilus as vehicle and adjuvant.

Lactobacilli are able to induce upregulation of co-stimulatory molecules in DCs with Th1 cytokines production and increase in Treg activity. This could explain the observed effectiveness of the prolonged administration of lactobacilli in the prevention of allergic disorders in infants and envisage the possible use of bacteria expressing the allergen for the specific immunotherapy of allergic diseases. Hence, we evaluated Streptococcus thermophilus (ST) expressing rBet v 1 as allergen delivery tool and adjuvant factor for immunotherapy in Betv1-sensitized mice. rBet v 1 gene was introduced and expressed in ST (ST[rBet v 1]). BALB/c mice were sensitized with rBet v 1 and then treated with either ST alone, ST[rBet v 1], or the combination of ST and rBet v 1, for 20 days. After 2 aerosol challenges, Treg frequency, in vitro allergen-induced cytokines, rBet v 1-specific IgE and IgG2a, and bronchial histology were made in harvested spleen, sera, and lung. Results were compared with those obtained from not-treated/sensitized mice. ST[rBet v 1] induced immunological and histological changes typical of successful SIT: increased frequency of Tregs and expression of Foxp3; decreased allergen-specific IgE/IgG2a ratio; decrease of in vitro rBet v 1-induced IL-4 from spleen cells; increased allergen-induced IL-10 and IFN-γ; drop of bronchial eosinophilia. ST and ST+rBet v 1 combination, even though induced a slight increase in the frequency of Tregs and moderate allergen-induced IL-10, were ineffective in reducing bronchial eosinophilia, allergen induced IL-4 and rBet v 1-specific IgE/IgG2a ratio. ST[rBet v 1] has tolerogenic and Th-1 skewing properties and efficiently delivers the allergen to the gut immune-system restraining and readdressing the established specific Th2 response toward the allergen in mice.